I've always missed being able to have some sense of the file size but now that I navigate with it, I don't know how I put up with this huge missing feature for so long.
Anyhow, I finally decided to fix it myself. This script should work in any GreaseMonkey/TamperMonkey type of extension. You have two viewing options for small files. You can either see > 1KB or something like 768 B, meaning bytes. Up to you!
It's not flawless; sometimes it may skip a file because the DOM is what it is or something else. Feel free to open any issue